Navigation Links
Coastal animals have their own tidal timer -- separate from the 24-hour body clock

University of Leicester researchers have revealed that coastal animals have their own biological tidal timer, which is separate from their 24-hour body clock.

Experts from the University's Department of Genetics have published a paper in Current Biology which reveals the discovery of an independent clock driving coastal animals' tidal rhythms.

The paper, Dissociation of Circadian and Circatidal Timekeeping in the Marine Crustacean Eurydice pulchra, follows nearly ten years of research by Leicester geneticists, along with colleagues at the Universities of Bangor, Aberystwyth and Cambridge.

The researchers observed the behaviour of Eurydice pulchra, the speckled sea louse which lives along the sandy shores around the UK coast.

Eurydice have a regular 12.4 hour swimming cycle matching the incoming tides which sees them actively swimming around to find food as the tide comes in, and burying themselves in the sand as the tide goes out.

Eurydice also have a 24 hour 'circadian' rhythm in pigmented cells called melanophores, which grow during the day (acting as sunscreen) and become smaller at night when they are not required.

It had been thought for many years that these patterns of tidal behaviour in coastal organisms were driven by the 24-hour circadian clock, the ubiquitous and genetically encoded 'body clock' which controls the rhythmic behaviour and physiology of almost every terrestrial higher organism, including humans.

But the new paper shows that tidal behaviour is not governed by the circadian clock but is instead controlled by a dedicated 12.4-hour "circatidal pacemaker".

The researchers caught Eurydice from the coast near Bangor every season and monitored their behaviour and clock molecules in laboratories at Bangor and Leicester.

The team were able to "turn off" Eurydice's circadian clock by genetically knocking down two of the key circadian clock genes, which they had identified.

They were also able to block the circadian cycle by exposing Eurydice to a constant bright light for many days.

With both of these genetical and environmental manipulations, the circadian rhythm in the sunscreen cells became severely disrupted, but the tidal swimming rhythm just kept on ticking every 12.4 hours.

This showed conclusively that the animals' tidal patterns are independent of their 24 hour circadian clock.

The researchers believe these results along with a parallel study on coastal worms published simultaneously in the journal Cell Reports on 26 September which came to a similar conclusion - suggest that many other coastal animals will have similar circatidal systems.

Principal investigator Professor Charalambos Kyriacou, Professor of Behavioural Genetics in the University's Department of Genetics, said: "Most coastal animals will have 24 hour rhythms in some aspects of their physiology, but their most important geophysical cycle is the tides coming in and out and so they have evolved circatidal rhythms to cope with this rapidly changing environment.

"Eurydice pulchra have both a 24 hour rhythm and a 12.4 hour rhythm, which relates to the gravitational pull of the moon on the earth's tides.

"People have speculated that the 24 hour clock could be driving the 12.4 hour clock, because all it would take is for two 24 hour clocks in the brain to work in antiphase with each other.

"This would give two approximate 12 hour rhythms. We have shown that if we knock down the genes that code for their 24 hour clock, the animal still has very robust tidal rhythms.

"This shows that the 12.4 hour clock is independent from the circadian clock. I expect tidal rhythms in many coastal organisms will follow this rule including insects, crabs, even plants."


Contact: Charalambos Kyriacou
University of Leicester

Related biology news :

1. Oceanographer Sylvia Earle kicks off Northeasterns Sustaining Coastal Cities Conference
2. Study finds maize in diets of people in coastal Peru dates to 5,000 years ago
3. Brown University scientists to discuss resilience of coastal communities at AAAS
4. Sustaining Coastal Cities Conference at Northeastern University
5. Preserve the services of mangroves -- Earths invaluable coastal forests, experts urge
6. Destroyed coastal habitats produce significant greenhouse gas
7. Clemson, Coastal Carolina universities to set hundreds of sensors in Savannah River
8. PSU study finds caffeinated coastal waters
9. Increasing levels of carbon dioxide in Arctic coastal seas
10. Personality interactions between animals may dictate outcomes in the wild
11. Relating animals to humans could help conservation projects
Post Your Comments:
(Date:11/17/2015)... Calif. , Nov. 17, 2015  Vigilant Solutions ... has joined its Board of Directors. ... Board after recently retiring from the partnership at TPG ... 107 companies with over $140 Billion in revenue.  He ... improvement across all the TPG companies, from 1997 to ...
(Date:11/16/2015)... , Nov 16, 2015  Synaptics Inc. (NASDAQ: ... interface solutions, today announced expansion of its TDDI ... touch controller and display driver integration (TDDI) ... smartphones. These new TDDI products add to the ... resolution), TD4302 (WQHD resolution), and TD4322 (FHD resolution) ...
(Date:11/12/2015)... 2015  Arxspan has entered into an agreement ... for use of its ArxLab cloud-based suite of ... partnership will support the institute,s efforts to electronically ... information internally and with external collaborators. The ArxLab ... the Institute,s electronic laboratory notebook, compound and assay ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... , November 24, 2015 ... new market research report "Oligonucleotide Synthesis Market by Product ... (PCR, Gene Synthesis, Diagnostic, DNA, RNAi), End-User (Research, Pharmaceutical ... published by MarketsandMarkets, the market is expected to reach ... in 2015, at a CAGR of 10.1% during the ...
(Date:11/24/2015)... ... November 24, 2015 , ... The Academy of Model Aeronautics ... (SIG), MultiGP, also known as Multirotor Grand Prix, to represent the First–Person View (FPV) ... Many AMA members have embraced this type of racing and several new model aviation ...
(Date:11/24/2015)... 24, 2015 --> ... report released by Transparency Market Research, the global non-invasive ... CAGR of 17.5% during the period between 2014 and ... Global Industry Analysis, Size, Volume, Share, Growth, Trends and ... testing market to reach a valuation of US$2.38 bn ...
(Date:11/24/2015)... 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) ... remaining 11,000 post-share consolidation (or 1,100,000 pre-share consolidation) ... B Warrants") subject to the previously disclosed November ... 2015, which will result in the issuance of ... the issuance of such shares, there will be ...
Breaking Biology Technology: